A/N: This one shot was inspired by turtle-sketches wonderful art on tumblr. You should really check her out her turtle fan art is a-ma-zing.
Ever since they started going topside, their life had become so very complicated. On one hand he was glad for the extra bit of freedom their vigilante lives offered them but on the other... humans. He would not argue the morality of helping people and stopping crime, saving innocents that seemed to fuel a new sense of purpose in Leonardo, that had Raphael less agitated when he was allowed to go for a run and had Mikey happier and spending more time on his sketches and less pranking them.
For Donatello it was different. He couldn't not help someone when they needed it. It was part of his nature. It wasn't because of some code of honour or anger towards those who'd prey on the weak. He felt their suffering in him, he needed to help them because it hurt him to see others hurt and he imagined it was similar with Mikey though his brother took the consequences much more lightly than he did. When those same humans he saved turned around and attacked him or his brothers, or yelled names at them, he felt something inside him twist.
"They just fear what they can't understand." Leonardo had told him calmly after a kid who they saved from a beating had then swung a metal pipe at them and called them monsters.
Donatello preferred to stay underground with his experiments and machines, spying humanity through a safe window called the internet so he wouldn't be hurt for being himself. Today though, he'd needed to go to the junkyard for some parts. He asked his brothers for help but they were busy and each gave their excuses, telling him to ask a different brother who they thought would be more available and he'd understood. For them, junkyard diving was a terribly tedious task, so he set out quietly alone thinking he wouldn't be long. He was wasting more time trying to convince one of them to come with him then the actual time it would take to find what he needed. He could take care of himself, it was no big deal.
Only it was now.
He woke up bound in chains on the floor in the back of a van. His head bumping against the bottom every time they drove over a crack in the road or a pothole. They'd gotten the jump on him. He wasn't sure who they were. Purple dragons? Maybe one of the lesser gangs?
"Why are you doing this?" He gasped out through his pain. He probably had a concussion and several broken bones. His body was screaming in agony.
He received no answer other than a sharp kick in the side, where there was no shell to protect his ribs. He decided to remain silent then. He still felt the weight of his phone in the pouch on the inside of his belt, tucked in the gap under the lip of his carapace. His family would be able to track him when they realised he was missing. He just had to stay alive until then.
The van stopped and the men got out and pulled him by the chains, dropping him unceremoniously on the floor before dragging him along. The docks. This was not good. He heard the clink of a lock closing and before he could open his mouth to make any sort of plea one of them spoke.
"Don Vizioso sends his regards." The thug said before rolling him over with a foot and plunging him into the watery depths at the end of the pier.
Donatello barely had a moment to take a deep breath before he went under, pulled by the weight that was attached to the end of his chains. His brothers couldn't save him now. Even with his turtle lungs he could probably only last around 45 minutes without surfacing for oxygen, maybe an hour. He wasn't even sure they knew he was missing.
He cursed in his head after realising there was no point in struggling. His wrists and ankles were cuffed to the links and the chain itself wrapped around his body tightly giving him no way of moving effectively to reach the shore. He tried to calm down his heart. He needed to give his brothers all the time he could get. Maybe they had already realised he was gone and tried to contact him. With his phone silenced he wouldn't know if they'd called or not and if they couldn't get a hold of him Leonardo knew how to track the phone and come find him. They could be on their way this very minute.
Time ticked by as he tried to meditate, then he tried to count in his head or resolve equations, anything to keep the despair at bay. He started feeling the burn in his lungs and pressure in his eyes and knew his time was running out.
At least they'll be able to find my body. He thought as he opened his eyes to the murky depths in time to see something quickly move out of his line of sight. It was too dark and too deep to see very far even with his keen eyesight. Maybe his brothers had come for him just in time?
Relief filled him and he tried to move a bit so they could see him. Perhaps they were having a hard time locating his precise whereabouts. He twisted his head around trying to see for himself and then it came into view again. It was a face, a human face.
Impossible.
She wasn't human. Now that she was right in front of him and with the tenuous light of the moon he could see her shape. A pale human woman down to her slim waist and the yellow body of a fish with a large nearly transparent tail fin.
Mermaids aren't real.
Her red hair floated around her as she regarded him curiously. She swam around him in a circle, delicate, webbed hands brushing over his body as she explored, tugging on his purple mask and protective pads playfully.
Maybe he'd already run out of oxygen, was already unconscious and this was all happening in his head.
Her fingers dabbed at an open wound on his side but he was too numb to respond. His eyes were locked on her, slightly dazed and he didn't think to try communicate with the only being who could save him until he noticed her expression change from curiosity to alarm when she began pulling at his chains and realised he was stuck underwater.
He decided to risk it. Maybe she couldn't understand, maybe this was all a fantasy in which case it wouldn't matter either way but he used up his last puff of air to yell "HELP" into the water, hoping for the best.
His vision started darkening around the edges and his body relaxed as it began to accept the void when he felt her hands on his cheeks, lifting his face and her mouth close around his.
His lungs filled with new air and he nearly sobbed into her mouth in relief as she breathed into him. When their lips parted she smiled at him and caressed his cheek tenderly before starting to pull at the chains again. He twisted and struggled in the chains, now he could afford to waste energy and breath trying to get free.
They weren't getting anywhere. He made a muffled "Mmmn!" sound to get her attention and she immediately pressed her lips to his again. This time he blushed and pulled away, shaking his head and trying to signal to the weight at the bottom, trying to drag it with his feet in the direction of the shore. She understood his intentions and tried to pull it by the chain, then push it along the muddy bottom but it was hardly budging. The most she managed to do was tilt it and roll the heavy block of cement onto its side advancing a little over a foot.
It would take forever this way but it was better than nothing, so they continued this way, moving slowly along the bottom. He called for her to breathe for him again a few times when he felt dizzy. He wasn't lasting as long now with the extra exertion and she smiled against his mouth as she did so each time without hesitation, rubbing her nose against his snout once she had filled him and giving him a sly wink one time when he had asked for air twice with hardly any wait in between.
A mermaid is flirting with me.
The crazy thought made the situation even more surreal than it already was, distracting him from his task. He wasn't sure how long he'd been underwater when he heard the unmistakable splash of someone diving into the water nearby. He tried to see who it was and by the time he turned his head to face his mermaid saviour she was nowhere to be seen.
His brothers picked the locks and pulled him out of the gelid water shortly after and the trip home was a blur. At some point he must have lost consciousness because the next thing he knew he was waking up in the darkened infirmary, a worried Leonardo slumped over in a chair by his side.
"I'm sorry." He whispered shakily when he woke to find Donatello regarding him silently. Don opened his arms and Leo leaned into him, sobbing quietly and carefully into his little brother whom he thought he had lost.
"How?" Leonardo asked him when he regained his calm composure.
"A mermaid." Donatello answered with a half shrug and a smile. Leo gave him a curious look but let him rest without any further questions.
Weeks later, a healed Donatello returned to the docks, determined to figure out if everything had been real or not. He hadn't convinced his brothers to let him go on his own but he managed to keep them waiting in the van and let him "get closure" in private. He jumped in and swam around for a while but didn't see her again.
Perhaps it had all happened in his head, maybe being underwater so long had triggered a hibernation instinct and his mind had dreamed the whole thing up as it slowed down his bodily functions to not need air for a long period of time and survive.
He managed to find the cement block with the chains still attached and examined them closely. Something caught his eye and he grinned, the weight of uncertainty lifting from his chest as he pulled his purple mask off and tied it to the end of one of the chains before heading back to his waiting brothers.
"Had a good swim?" Raphael asked and Don only answered with a nod. "Was about to go after ya." Don climbed into the back of the van with Michelangelo and Raph turned the engine and began driving home.
"Where's your mask?" Leonardo asked him after a few minutes.
"I have more at home." He waved away his concern. They drove in pensive silence for a while longer before another spoke up.
"What's that? Can I see?" Mikey pointed at Don's wrist and he lifted it for his brother to inspect.
"It's a bracelet made of braided reeds and seashells." He replied with a warm smile.
Done with his inspection, Mikey released his wrist. "Where did you get it from?"
"The bottom of the ocean." He answered simply.
Leonardo's head snapped around to regard Donatello's wistful smile intently. "Your mermaid?" He asked after a while.
"Mhmmm." Donatello hummed and nodded as he fingered the unassuming trinket.
"Mermaid. Right." Raphael spoke up and Michelangelo laughed at the thought.
Don smiled to himself as he turned the bracelet around and around on his wrist the whole way home, thoughts turned inward, ignoring Raph and Mikey's playful banter and Leonardo's curious glances.